In general, a dome key type is widely used as an input unit of a portable terminal.
However, the dome key type is so standardized that an implementable user interface is exceedingly restricted. In addition, it is necessary to have a space for a circuit, a component or a tool such as a dome key, a switch, a keypad and an electrostatic discharge (ESD) protecting element. In order to solve such problems, a touch screen type is used. However, even when using the touch screen type, a main function key is implemented by the dome key type due to the limit of the implementation of user interface using a graphic and the user friendliness.
FIG. 1 is a front view of a conventional portable terminal 100.
Referring to FIG. 1, the conventional portable terminal 100 includes a touch screen 190. For user's convenience, the terminal 100 includes a SEND key 110, a BACK key 120, an END key 130, a volume increase key 140, a volume decrease key 150, a multi function key 160, a hold key 170 and a camera key 180. The SEND key 110, the BACK key 120, the END key 130, the volume increase key 140, the volume decrease key 150, the multi function key 160, the hold key 170 and the camera key 180 are implemented as dome keys.
Various components are necessary so as to sense the input of the dome keys 110-180. For the implementation of the dome key type, it is necessary to have a mounting space. For this reason, problems related to restriction of shape, restriction of designing hardware and instrument, and increase of costs can occur. Moreover, due to a component and a structure which are necessary when using the dome key type (e.g., a key Panel Board Assembly (PBA) or a Key Flexible Printed Circuit Board (FPCB)), problems related to Radio Frequency (RF) and Global Positioning System (GPS) characteristic deterioration, audio performance degradation due to speaker resonance space reduction, wetting/moisture invasion due to key structure addition, and process or progressive one piece/set defect may occur.